System and method for realistic terrain simulation

Abstract

A technique and system for the realistic simulation of visual scenes reduces the three-dimensional computation to two additions and further reduces the need for three-dimensional computations by displaying several screen pixels per three-dimensional computation. The approach when implemented in hardware or software significantly speeds up scene generation time while improving the resolution and realism of the rendered scene.

I claim: 
     
       1. A method of generating a frame of a perspective visual scene, comprising the steps of: a) determining the position and heading of an observer in relation to a gaming area bounded by the observer's field of view;   b) incrementing the observer's position along the heading of the observer by one unit;   c) retrieving quadrant data for a quadrant located at the observer's new position;   d) comparing the quadrant data at the observer's new position to an altitude of the observer, wherein if the quadrant data is less than the altitude of the observer, incrementing a quadrant step vector and repeating step c;   e) determining a distance from the observer to an object of interest;   f) selecting a database to be used dependent on the distance from the observer to the object of interest;   g) sampling the height data of the object of interest at the current position;   h) comparing the height data at the current position with the current elevation value;   i) drawing a line for any part of the height data that is above the current elevation;   j) incrementing one unit farther away from the observer;   k) repeating steps b through j until the entire visual scene is rendered; and   l) displaying the visual scene on a display device.   
     
     
       2. The method of claim 1, wherein the set of selecting a database further comprises: expanding an expansion token if the object of interest is closer to the virtual observer than a predetermined distance; and   rendering a feature represented by the expanded expansion token.   
     
     
       3. The method of claim 1, wherein the step of drawing includes the step of scaling the length of the line to be drawn in accordance with the altitude of the observer and the distance of the observer from the object of interest and the step of reducing the length of the line to be drawn by the height of the previously drawn line. 
     
     
       4. The method of claim 3, further comprising the step of storing the height of the object of interest in a buffer. 
     
     
       5. The method of claim 4, wherein the step of incrementing the observer's position along the heading of the observer includes calculating a step vector having a value of a height component and wherein if the value of the height component is less than the stored value of the height of the object of interest, incrementing the observer's position along the heading of the observer by one unit. 
     
     
       6. A method of generating a frame of a perspective visual scene, comprising the steps of: a) determining the position and heading of an observer in relation to a gaming area;   b) incrementing the observer's position along the heading of the observer by one unit;   c) retrieving quadrant height data for a quadrant located at the observer's new position;   d) determining from the quadrant height data at the observer's new position whether any feature located within the quadrant is visible to the observer, wherein if no features are visible to the observer, incrementing a quadrant step vector and repeating steps c and d;   e) determining a distance from the observer to a first visible feature in the quadrant;   f) selecting a database to be used dependent on the distance from the observer to the first visible feature;   g) sampling the height data of the first visible feature at the current position;   h) comparing the height data at the current position with the current elevation value;   i) drawing a line for any part of the height data that is above the current elevation;   j) incrementing one unit farther away from the observer;   k) repeating steps e through j until all of the visible features located within the quadrant are rendered;   l) incrementing one unit farther away from the observer;   m) repeating steps b through l until the entire frame of the visual scene is rendered; and   n) displaying the visual scene on a display device.   
     
     
       7. The method of claim 6, wherein the set of selecting a database further comprises: expanding an expansion token if the feature is closer to the observer than a predetermined distance; and   rendering an object represented by the expanded expansion token.   
     
     
       8. A method of generating a frame of a visual scene to be displayed on a display device, comprising the steps of: a) determining a position, heading and altitude of an observer in relation to a gaming area;   b) calculating a step vector in accordance with the position, heading and altitude of the observer;   c) incrementing the step vector by one unit;   d) determining a distance from the observer to an object of interest;   e) selecting a database to be used dependent on the distance from the observer to the object of interest;   f) sampling the height data of the object of interest at the current position;   g) scaling the height of the object of interest at the current position in accordance with the position, heading and altitude of the observer;   h) comparing the height data at the current position with the current elevation value;   i) drawing a line for any part of the height data that is above the current elevation;   j) storing the a value for the new current elevation in a buffer;   k) incrementing the step vector by one unit;   l) comparing a height value of the step vector to the stored value for the new current elevation, and wherein if the height value of the step vector is greater than the stored value, repeating steps d through k, otherwise repeating steps k through 1, until the entire visual scene is rendered;   m) displaying the visual scene on a display device.   
     
     
       9. The method of claim 8, wherein the step of selecting a database further comprises: expanding an expansion token if the object of interest is closer to the observer than a predetermined distance; and rendering a feature represented by the expanded expansion token.   
     
     
       10. The method of claim 8, wherein the step of incrementing the step vector by one unit includes the steps of: retrieving quadrant data for a quadrant located at the observer's position;   comparing the quadrant data at the observer's position to the altitude of the observer, and wherein if the quadrant data is less than the altitude of the observer, incrementing a quadrant step vector and repeating the steps of retrieving quadrant data and comparing the quadrant data to the altitude of the observer.